Why do you measure overhead on your server? Let’s
compare it with measuring overhead in any business. Each business has
monthly rent, utilities, and labor costs. These types of fixed costs are
overhead. This analogy helps illustrate the fact that every server has
some base resources that are overhead to the system.
Security can add overhead
to any application and server. Depending on your requirements, it could
add a delay and affect overall application performance. Security also
costs some performance gains. For example, depending on your
architecture, you can expect Secure Sockets Layer (SSL) processing to
affect overall performance, both at the server and application level.
Following is an example of
how you can establish the baseline for your server and worker process
size (w3wp.exe) before you put any applications, modules, and load on
the system. The example uses a server with Windows Server 2008
Enterprise edition with the Default IIS 7.0 install workload:
1. | Install the Default IIS workload, which serves static content with anonymous access.
| 2. | Open Internet Explorer and type http://localhost.
| 3. | After
you browse http://localhost, a w3wp.exe process should show up in
Windows Task Manager. Click the Processes tab and locate the memory
footprint (for this example, it’s about 3.1 megabytes [MB]).
| 4. | If
you want to see which dynamic-link libraries (DLLs) are loaded into the
w3wp.exe worker process, open a command prompt and type tasklist /M /FI “Imagename eq w3wp.exe”. Here is an example of the output you will see.
|
Image Name PID Modules
===================== ======== ============================================
w3wp.exe 3572 ntdll.dll, kernel32.dll, ADVAPI32.dll,
RPCRT4.dll, msvcrt.dll, USER32.dll,
GDI32.dll, ole32.dll, IISUTIL.dll,
CRYPT32.dll, MSASN1.dll, USERENV.dll,
Secur32.dll, WS2_32.dll, NSI.dll,
IMM32.DLL, MSCTF.dll, LPK.DLL,USP10.dll,
NTMARTA.DLL, WLDAP32.dll, PSAPI.DLL,
SAMLIB.dll, w3wphost.dll, OLEAUT32.dll,
nativerd.dll, XmlLite.dll, IISRES.DLL,
rsaenh.dll, mscoree.dll, SHLWAPI.dll,
comctl32.dll, mscorwks.dll, MSVCR80.dll,
CLBCatQ.DLL, mlang.dll, iiscore.dll,
W3TP.dll, w3dt.dll, HTTPAPI.dll,slc.dll,
faultrep.dll, VERSION.dll, NLAapi.dll,
IPHLPAPI.DLL, dhcpcsvc.DLL, DNSAPI.dll,
WINNSI.DLL, dhcpcsvc6.DLL, mswsock.dll,
winrnr.dll, napinsp.dll, wshtcpip.dll,
wship6.dll, rasadhlp.dll, cachuri.dll,
cachfile.dll, cachtokn.dll,cachhttp.dll,
compstat.dll, defdoc.dll, dirlist.dll,
protsup.dll, static.dll, authanon.dll,
modrqflt.dll, custerr.dll, loghttp.dll,
iisreqs.dll, WSOCK32.dll, authbas.dll,
authsspi.dll, NETAPI32.dll
Note Although
this list of DLLs appears to include a lot of entries, most of the DLLs
are required by the core IIS engine. Some modules such as Default
Documents (defdoc.dll) are optional and could be removed. This example
uses the Default install of IIS. If necessary, you could reduce the
number of optional role services, which would reduce the number of DLLs
loaded. The only way to really know whether or not you can reduce the
number of optional role services is to bring up a server in an isolated
environment and test your configuration. |
Here is an example
from a server running Windows Server 2008 Server Core. The w3wp.exe
process is approximately 2.5 MB in this example.
Image Name PID Modules
===================== ======== ============================================
w3wp.exe 804 ntdll.dll, kernel32.dll, ADVAPI32.dll,
RPCRT4.dll, msvcrt.dll, USER32.dll,
GDI32.dll, ole32.dll, IISUTIL.dll,
CRYPT32.dll, MSASN1.dll, USERENV.dll,
Secur32.dll, WS2_32.dll, NSI.dll,
IMM32.DLL, MSCTF.dll, LPK.DLL,USP10.dll,
NTMARTA.DLL, WLDAP32.dll, PSAPI.DLL,
SAMLIB.dll, w3wphost.dll, OLEAUT32.dll,
nativerd.dll, XmlLite.dll, IISRES.DLL,
rsaenh.dll, CLBCatQ.DLL, mlang.dll,
comctl32.dll, SHLWAPI.dll, iiscore.dll,
W3TP.dll, w3dt.dll, HTTPAPI.dll,slc.dll,
faultrep.dll, VERSION.dll, mswsock.dll,
DNSAPI.dll, NLAapi.dll, IPHLPAPI.DLL,
dhcpcsvc.DLL, WINNSI.DLL, dhcpcsvc6.DLL,
wshtcpip.dll, wship6.dll, cachuri.dll,
cachfile.dll, cachtokn.dll,cachhttp.dll,
compstat.dll, defdoc.dll, dirlist.dll,
protsup.dll, static.dll, authanon.dll,
modrqflt.dll, custerr.dll, loghttp.dll,
iisreqs.dll, WSOCK32.dll, gzip.dll
This
worker process baseline exercise shows you how to determine how big
your w3wp process will be and which DLLs are loaded. If you add modules,
you can run through the exercise again and see how your memory
footprint has changed.
Table 1 lists the new WAS_W3WP Reliability And Performance Counter (perfmon) counters in IIS 7.0.
Table 1. WAS_W3WP Counters| Counter Name | Description |
|---|
| Total Health pings | Total number of health pings received by the process | | Total Runtime Status Queries | Total number of Runtime Status queries received by the process | | Health Ping Reply Latency | Time, in 100-nanosecond intervals, taken by worker process to reply to last health ping | | Active listener channels | Number of currently active listener channels in the worker process | | Active protocol handlers | Number of currently active protocol handlers in the worker process | | Total WAS Messages Received | Total number of messages received by the worker process from Web Admin Service | | Messages Sent to WAS | Total count of messages sent to WAS | | Total Requests Served | Total
number of requests served by the worker process; this counter is
meaningful only when request-based recycling is enabled for the
application pool | | Total Messages Sent to WAS | Total number of messages sent to Web Admin Service by the worker process |
The new W3SVC_W3WP Reliability and Performance Counter (perfmon) counters in IIS 7.0 are listed in Table 2.
Table 2. W3SVC_W3WP Counters in IIS 7.0| Counter Name | Description |
|---|
| Total HTTP Requests Served | Total number of HTTP requests served by the worker process | | Requests/Sec | HTTP requests/sec being processed by the worker process | | Active Requests | Current number of requests being processed by the worker process | | Total Threads | Total number of threads available to process requests in the worker process | | Active Threads Count | Number of threads actively processing requests in the worker process | | Maximum Threads Count | Maximum number of threads to which the thread pool can grow as needed | | Current File Cache Memory Usage | Current number of bytes used by user-mode file cache. | | Maximum File Cache Memory Usage | Maximum number of bytes used by user-mode file cache. | | Output Cache Current Memory Usage | Current number of bytes used by output cache | | Current Files Cached | Current number of files whose contents are present in user-mode cache | | Total Files Cached | Total number of files whose contents were ever added to the user-mode cache (since service startup) | | File Cache Hits | Total number of successful lookups in the user-mode file cache (since service startup) | | File Cache Misses | Total number of unsuccessful lookups in the user-mode file cache (since service startup) | | File Cache Flushes | Total number of files removed from the user-mode cache (since service startup) | | Active Flushed Entries | Number of file handles cached in user-mode that will be closed when all current transfers complete | | Total Flushed Files | Total number of file handles that have been removed from the user-mode cache (since service startup) | | Current URIs Cached | URI information blocks currently in the user-mode cache | | Total URIs Cached | Total number of URI information blocks added to the user-mode cache (since service startup) | | URI Cache Hits | Total number of successful lookups in the user-mode URI cache (since service startup) | | URI Cache Misses | Total number of unsuccessful lookups in the user-mode URI cache (since service startup) | | URI Cache Flushes | Total number of URI cache flushes (since service startup) | | Total Flushed URIs | The number of URI information blocks that have been removed from the user-mode cache (since service startup) | | Current Metadata Cached | The number of metadata information blocks currently present in user-mode cache | | Total Metadata Cached | Total number of metadata information blocks added to the user-mode cache (since service startup) | | Metadata Cache Hits | Total number of successful lookups in the user-mode metadata cache (since service startup) | | Metadata Cache Misses | Total number of unsuccessful lookups in the user-mode metadata cache (since service startup) | | Metadata Cache Flushes | Total number of user-mode metadata cache flushes (since service startup) | | Total Flushed Metadata | Total number of metadata information blocks removed from the user-mode cache (since service startup) | | Output Cache Current Items | Number of items current present in output cache | | Output Cache Total Hits | Total number of successful lookups in output cache (since service startup) | | Output Cache Total Misses | Total number of unsuccessful lookups in output cache (since service startup) | | Output Cache Total Flushes | Total number of flushes of output cache (since service startup) | | Output Cache Total Flushed Items | Total number of items flushed from output cache (since service startup) | | File Cache Hits / sec | Rate of successful lookups in file cache during last sample interval | | Metadata Cache Hits / sec | Rate of successful lookups in metadata cache during last sample interval | | Uri Cache Hits / sec | Rate of successful lookups in URI cache during last sample interval | | File Cache Misses / sec | Rate of unsuccessful lookups in file cache during last sample interval | | Metadata Cache Misses / sec | Rate of unsuccessful lookups in metadata cache during last sample interval | | Output Cache Misses / sec | Rate of unsuccessful lookups in output cache during last sample interval | | Uri Cache Misses / sec | Rate of unsuccessful lookups in URI cache during last sample interval | | Total HTTP Requests Served | Total number of HTTP requests served by the worker process | | Requests / Sec | HTTP requests / sec being processed by the worker process |
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